Justin Bieber performs at the Colonial Life Arena in Columbia, South Carolina, Monday.ZUMAPRESS.com

The Justin Bieber battle outside a Hamptons club started over an attractive waitress and a bow tie, according to witnesses.

A brawl involving the superstar’s security and other clubbers kicked off in the early hours of Sunday outside South Pointe nightclub in Southampton.

Police are now investigating members of Bieber’s team of bodyguards who are accused of assaulting a male clubber, who was hospitalized.

A witness tells us, “Justin left the club with two waitresses. But the guys on the next table were not happy. One of the waitresses – a very attractive blonde – was flirtatiously wearing a bow tie, which one of the guys on the next table had loaned to her.

“As she got into Bieber’s SUV, the guys chased her out, saying they wanted the bow tie back. Bieber’s security pushed back, and a scuffle started.

“As Bieber and his team drove away, someone threw a rock at his car. Bieber jumped out of the sun roof and got on the hood of the car, while his security knocked the guy to the floor.”

Police were called by the victim, who was taken to Peconic Bay Medical Center and released yesterday. Cops have interviewed the club’s owner, security and staff. It is believed some of the altercation was caught on security cameras.

South Pointe’s idiotic rep Melanie Weitzner initially claimed to The Post that Bieber’s visit had been drama free. Despite numerous witnesses that tell us otherwise, today the witless Weitzner continued to insist,” There was no incident in the club or on the premises.”

A spokesman for Bieber added, “Justin wasn’t involved in the altercation.”

Despite all the drama, we are told the party carried on for Bieber, who took the two waitresses and the club’s DJ on to a private bash at a private oceanfront property.